The  California Department of Social Services shall notify foster family agency to act immediately to remove from the home are bar from entering the home any person  who has been convicted off or is awaiting trial for a sex offense against a minor any person who's been convicted of a felony and other crimes.

Upon notification, the foster family agency shall ensure a resource family complies with the notice. If the individual who is the subject of the notice is the resource family the resource family spouse or independent adult the foster family agency shall notify the state. 

Criminal record exemptions may be granted by the state using the exemption criteria.

The state shall, in writing, separately notify the individual, and the foster family agency, when the individual has been convicted of a crime for which an exemption may not be granted.

Only the notice to the individual shall indicate the specific criminal conviction(s) for which an exemption may not be granted, including the crime, date, and location of the conviction, and shall include a copy of the complete criminal offender record information received from the California Department of Justice.
 

Here is a list of crimes that cannot be exempted.